The Astatic Noise-Canceling microphone is designed for close talking handheld applications in quality sound installations where background noise is a problem. The omnidirectional dynamic microphone s frequency response especially tailored for voice communications provides a crisp clear highly intelligible sound with 360 minimization of background noise. A soft lip-guard is positioned to assure proper close-talk voice spacing by the microphone s operator. The dynamic cartridge has a rugged polyester diaphragm that resists moisture temperature extremes most acids alkalines and solvents. Molded in high-impact Cycolac the 631L microphone comes with a permanently attached heavy-duty four-conductor two-shielded coil cord. The low impedance Astatic Noise-Canceling Microphone is simple to operate. A trouble-free DPDT long-life switch is factory-wired normally open.